Not to jump on an old thread but I was driving down 95 today and suddenly in my Acura (RL) the same P0420 code popped up and the check engine light came on-- along with a check emissions warning.

I have 77K on this car-- just wondering if the common workaround for this was the replace the Catalytic converter in your cars? I know we may have different vehicles-- but under the same Honda family, the architecture of these cars are still the same in may ways...just trying to see if I may need to make sure the CAT gets replaced by 80K